A geographic information system (GIS) may include any system that captures, stores, analyzes, manages, and presents data that are linked to location. One field of work where GIS data is useful is in various types of surveying. For example, construction surveying may involve staking out reference points on a piece of land that guide the construction of new structures such as roads or buildings. In such a case, it is important to accurately establish geographic reference points. Similarly, a land surveying may involve marking out the metes and bounds of a property based on a legal description, and legal issues may arise if construction results in unintended incursion across or near property lines.
Modern surveyors use sophisticated tools to determine accurate location of reference points on land and water, such as precision levels, theodolites, tribrachs, laser distance meters, etc. Some aspects of a project may be highly sensitive to the accuracy of reference points, and some of the reference points may have been defined by others. For example, it is usually important to accurately define the property boundaries to ensure that structures are not placed too close to property lines, and proper placement of the property lines require an accurate description of the boundaries (e.g., via a plat map or legal description) and correct interpretation of that description.
Similarly, a construction project may need to take into account any pre-existing subsurface structures. A project may need to hook up to a buried structure (e.g., running a new utility line) and/or may be need to excavate nearby to a known subsurface structure. In such a case, it is important the structure is not damaged by digging equipment. The location of those subsurface structures may have been mapped by other entities, and the accuracy of those mappings may at times be suspect.
It will be appreciated that there is benefit to providing access to GIS data to many individuals who may be involved in a project. For example, construction workers and supervisors may continually be on-site, and therefore may be the first to discover any errors in the survey and/or in data on which the survey was based. In some cases (e.g., breakage of a natural gas line), the consequences of such errors can be fatal. In other cases (e.g., location of a foundation too close to a property line) the results may be expensive to correct. Accordingly, there is a need to increase both the availability and ease of use of GIS data so that non-specialists can utilize this data in their day-to-day activities.